Single sign on in ASP.net and WCF

Question

Hi ,

I have hosted my web site in "Dev.www.testing.com" and hosted WCF services in "Dev-app.testing"(there are 3 machines under this domain-load balancer comes here and request will go to one of these servers based on availablity.)

I am using HttpContext.current.Items in my web application and accessing the same from WCF.

1) If I hosted Web and WCF services in my local machine it is working fine(HttpCOntext is sharing.)

2) If I deploy Web in one of the app server (Dev-app.testing) and WCF services in other 2 servers it is working fine, HttpContext is sharing if Machinekey is same for Web and WCF projects

3) If I deploy Web project(in Dev.www.testing.com) in this server and WCF services in Dev-app.testing(Machinekey is same) , HttpCOntext is not sharing.

Please give the solution.

I am breaking my head since a week.